Group III-V compound semiconductors, such as GaN and AlGaN, are widely used for optoelectronics and electronics because of many advantages, such as easily controllable wide band gap energy.
In particular, light emitting elements, such as light emitting diodes or laser diodes, which use group III-V or II-VI compound semiconductors, are capable of emitting visible and ultraviolet light of various colors, such as red, green, and blue, owing to development of element materials and thin film growth techniques. These light emitting elements are also capable of emitting white light with high luminous efficacy through use of a fluorescent substance or color combination and have several advantages of low power consumption, semi-permanent lifespan, fast response speed, safety, and environmental friendliness, as compared to conventional light sources, such as fluorescent lamps and incandescent lamps.
Accordingly, application fields of the light emitting elements are expanded to transmission modules of optical communication units, light emitting diode backlights to replace Cold Cathode Fluorescence Lamps (CCFLs) which serve as backlights of Liquid Crystal Displays (LCDs), white light emitting diode lighting apparatuses to replace fluorescent lamps or incandescent lamps, vehicular headlight, and traffic lights.
In a lighting apparatus or a vehicular headlight, s light emitting element package having a plurality of light emitting elements disposed in one unit may be used and each light emitting element may receive current using a method, such as wire-bonding.
FIG. 1 is a view illustrating an arrangement in a light emitting element package.
A plurality of light emitting elements 100 is arranged in four columns and two rows and the respective light emitting elements 100 are bonded by wires 110 and 115. The neighboring light emitting elements 100 are separated from each other by a distance d1 in the vertical direction and a distance d2 in the horizontal direction. When the separation distances between the neighboring light emitting elements 100 are greater than d1 and d2, dark regions may be generated.
FIG. 2 is a view illustrating formation of dark regions in a three-row light emitting element package.
A plurality of light emitting elements 100 and 100′ is arranged in four columns and three rows and the respective light emitting elements 100 and 100′ are bonded by wires 110 and 115. When the neighboring light emitting elements 100 are arranged such that they are separated from each other by a distance d1 in the vertical direction and a distance d2 in the horizontal direction so as to prevent generation of dark regions, it is difficult to assure spaces required to perform wire bonding of the light emitting elements 100′ disposed at the inside.
That is, when light emitting elements are arranged in three or more rows, spaces for wire-bonding of light emitting elements which are not adjacent to the outside are required and these spaces may be represented as dark regions in a light emitting element package.